Micromod MOD: 1800P - MOD 30ML Identity Module (Version 2) Algorithms, Tables and Sequential Logic Functions - Manual (Page 61)

Logic Functions - Book 2
TIMER BLOCK
8-53
8.7 TIMER BLOCK (TM)
The Timer Block is used to perform timing functions for the instrument such as delayed start,
delayed stop, pulse duration, interval timing, or periodic self reset timing. When enabled, the
timer is a free running timer that adds or subtracts the elapsed time between and during
executions (Group Scan Interval from the interface block). A timer can be configured as an up
or down timer for a maximum duration of 1193 hours, 2 minutes, 47.295 seconds
(1193:02:47.295). The user has access to several control functions as database attributes.
These include:
•
Direction allows the timing direction (up/down) to be controlled
•
Reset resets the time value to the reset input value
•
Reset Value used to load a user-definable reset value
•
Disable allows the timer to be held at its current value
•
Wrap allows the timer to recycle when limit is reached and continue timing
•
Limits ‘stop’ values for count up or count down directions
Available to the user as block outputs are the timer value as well as two status indicators that
the timer has reached a limit value. A functional block diagram of the block is shown in Figure
8-27. The timer block display, which is used to configure the block, is shown in Figure 8-28.
BAD
TRUE
NONE
Input Status
Discrete LSP
Discrete LSP
Timing Signal
DOWN
HLSTAT
LLSTAT
Msec Time Value
Msec_time LSP
TIME
UP
Discrete LSP
Direction
Timer
(See Timing Diagrams)
FALSE
Disable
Reset Value
Reset
State
RUN, HOLD,
OFF, DEBUG)
Loop Scan
Group
Group Scan Interval
Bad Inputs
(Accepted,
Rejected)
High
Limit
Low
Limit
Quality Check
BAD
GOOD
GOOD
BAD
GOOD
HLSTATQ
TIMEQ
LLSTATQ
Auto
Wrap
Reset
Command
NO
YES
Figure 8-27. Functional Block Diagram, Timer Block